The Brain Institute, University of Utah, Salt Lake City, UT, USA.
Neurobiol Learn Mem. 2010 Mar;93(3):415-21. doi: 10.1016/j.nlm.2009.12.008. Epub 2010 Jan 13.
The prefrontal cortex is thought to be critical for goal-directed action and the hippocampus is known to be importantly involved in spatial memory. Several studies have been suggestive of a role for the orbitofrontal cortex (OFC) in spatial navigation. However, the medial prefrontal cortex (mPFC) receives projections directly from the intermediate CA1 (iCA1) region of hippocampus and this link may be critical for spatial navigation. The purpose of the present investigation was to test the performance of rats receiving bilateral or disconnection infusions of lidocaine into OFC, mPFC, or iCA1 to determine the contribution of these structures to encoding and retrieval of spatial memory using the Hebb-Williams maze. A total of 92 male Long-Evans rats received chronic bilateral, contralateral, or ipsilateral implantation of cannulas into OFC, mPFC, or iCA1. Prior to testing on day 1 or day 2, subjects received central infusions of saline or lidocaine. The number of errors committed on the first five trials compared to the second five trials of day 1 was used to determine encoding, whereas retrieval was determined by comparing the second five trials of day 1 with the first five trials of day 2. The present findings suggest that mPFC and iCA1 are necessary and interact during encoding and retrieval; however, the OFC does not appear to be essential for either process. While the nature of the interaction between mPFC and iCA1 during encoding and retrieval is unclear, it may be supported by the integration of goals and spatial cues or strategy switching.
前额皮质被认为对目标导向行为至关重要，而海马体则被认为对空间记忆有重要作用。有几项研究表明眶额皮质（OFC）在空间导航中起作用。然而，内侧前额皮质（mPFC）直接接收来自海马体中间 CA1（iCA1）区域的投射，这种联系对于空间导航可能至关重要。本研究的目的是测试接受双侧或单侧利多卡因输注到 OFC、mPFC 或 iCA1 的大鼠的表现，以确定这些结构对使用 Hebb-Williams 迷宫编码和检索空间记忆的贡献。共有 92 只雄性 Long-Evans 大鼠接受了双侧、对侧或同侧慢性植入 OFC、mPFC 或 iCA1 导管。在第 1 天或第 2 天进行测试之前，受试者接受了生理盐水或利多卡因的中央输注。将第 1 天的前 5 次试验与第 1 天的后 5 次试验相比，确定编码，而通过将第 1 天的后 5 次试验与第 2 天的前 5 次试验进行比较，确定检索。本研究结果表明，mPFC 和 iCA1 在编码和检索过程中是必要的，并且相互作用；然而，OFC 似乎对这两个过程都不是必需的。虽然 mPFC 和 iCA1 在编码和检索过程中的相互作用的性质尚不清楚，但它可能是通过目标和空间线索的整合或策略转换来支持的。
